Part II: Organizational Prerequisites for Smart Materials, Automatic Identification, and Quality
Chapter 11: Practical Implementations of the DCS Solution
11.1 Case Study with the Classification of Engineering Parts
Chapter 11: Practical Implementations of the DCS
1. The taxonomic organization of parts was made independent of classification of machines to which these belonged.
2. Particular attention was paid to classification of generalized parts useful to more than one machine.
The concepts underpinning these two premises are interrelated. The wisdom of the approach being chosen was documented by a preliminary study that demonstrated the importance of instituting a general reference category for spares, rather than locking oneself into the classification of machines to which these spares belong. Another premise observed in the organizational work is that group sorting (within DCS) would be accomplished along the line of employment of a given piece. This brought into perspective the different levels of usage that the pieces have.
Both the primary and the secondary criteria were studied in the course of the classification work. Exhibit 11.1 is a reminder of the process that Chapter 10 introduced. The family can be located through KL coordinates in the database matrix of DCS, the group through MN coordinates, and the class by means of PQ. Theoretically, up to one million classification possibilities exist. However, because a taxonomical system must allow for expansion, the possibilities are in reality much less. Their exact number depends on the population to which this system will be applied and on the objectives to be met.
Exhibit 11.1: A Practical Application of Classification Matrices in the Manufacturing Industry
Experience suggests that less than 60 (out of 100) families are used in the original design and that, subsequently, no more than 30 to 40 of the 100 possibilities are taken in any given group and (subsequently) class. Notice, however, that expandability can be ensured by converting the
classification system's radix 10 to, for example, 16. This makes more columns and rows available by increasing the size of the reference classification matrix.
It would be illogical to think that one and only one method of classification work would be used within a multinational firm, on a global scale. What is, however, advisable is to have some general classification rules to guide the hand of the analysts in their taxonomical efforts. As an example, the motor reduction gear shown in Exhibit 11.2 is classified within the DCS matrix in the family dedicated to machines to which it belongs (see Chapter 10, family 86 in Exhibit 10.4). The 10 × 10 matrix of this family might, for example, be constructed to represent:
By column, type of electromechanical equipment
By row, variations in reduction gear
Exhibit 11.2: Classifying a Motor Reduction Gear Within the DCS System
Entry into the matrix is by column and row — in that order. Within the family, the column-and-row intersection defines the group. The two class digits may, for example, classify voltage and horsepower.
This example shows the flexibility of the classification system under discussion and the ability to customize the taxonomy.
Component parts of the couple will also be classified, but in a different family. In Chapter 10, Exhibit 10.4, the family for parts is 82. One group in this family is dedicated to shells; both the shell of the motor and the reduction gear have their pigeonholes. The two, however, will be further distinguished by means of class digits. Motor shell and the reduction gear will be taxonomically distinguished from one another.
Because they are assembled parts, the rotor and stator will also fall into their own groups in family 83.
Their place is a group matrix column dedicated to electrical components. The gear and the axis will be in family 82, each in its own group. The numbers of the families are only indicative, to keep up with the example provided throughout Chapter 10. It is evident that each company will develop its own
classification matrix.
In the specific case study presented in this chapter, organization and classification benefited from an analysis of day-to-day utilization needs, including technical specs, production scheduling, inventory control, cost accounting, purchasing, quality inspection, and customer handholding. This number of variables suggested the choice of ways and means that avoided a complex structural solution.
Throughout the classification and identification effort, efficiency and utility were ensured by considering the eventual users of the coding system, by sampling their specific requirements expressed in the course of the last five years, and through personal interviews to update the reference to such needs.
The following definitions put forward by this project help in explaining the chosen approach.
Part (P)
Elementary components — or considered as such by convention: a part of machines or other equipment, or one that becomes a part after simple adjustment or adaptation without changing its fundamental dimensions.
Part of Level "A" (PA)
This had to be identified by type and supplier. For PA, one computer-based envelope has been instituted by basic code. The focus was engineering specs. Another mini-file was created for the individual part in connection with the suffix.
The origin identified the supplier, including parts internally made by the company and its subsidiaries.
Further definiens connected to the origin started with identification of the original supplier of this <bc>.
Second sourcing and other alternatives were also identified. Pointers/anchors connected this reference to supplier files, cost files, just-in-time files, and quality control files in the database.
Exhibit 11.3 presents the DCS structure in this particular application. A hexa-decimal ID code was used.
The reader will appreciate that, except for the further definiens connected to supply chain <o>, this ID/CC diagram is not different than the one seen in Chapter 10.
Exhibit 11.3: A Bird's-Eye View of the Parallel Code System, Including Taxonomy, Further Definiens, and Identification, As Used in the Case Study
Part of Level "B" (PB)
This is identified only by type. For parts B, a <bc> file is established for engineering specifications. It includes no individualized supplier sheets.
Part of Level "C" (PC)
Semi-identified parts, classified (with only a few exceptions) up to level x1 (as discussed below). In most cases, the x2x3 further definiens are not utilized in connection with PC. When complete part identification is not necessary, the values x2 = 9, x3 = 9 have been used.
The engineering vice president of the company on which this case study is based paid considerable attention to the cultural change of his personnel. Since until this implementation the department had kept microfiche files and these were kept in what in company jargon was known as "envelopes," he designed the schema in Exhibit 11.4 which provided for the transition between microfiche files and optical disk storage organized along the DCS methodology. Practical examples on computer-aided design (CAD) demonstrated that parts classification had to be enriched by three groups of further definiens:
x0 … x7, for <bc>
y0y1, for <s>
z0 … z5, for <o>
Exhibit 11.4: The Concept of a Logical Envelope in Connection with Classification/Identification
where
x0 = First field (one digit) x0 = 0 to x0 = 8 used for sorting, pursuing the classification of taxonomy in terms of secondary technical criterion, x0 = 9 does not currently serve an information purpose
x1 … x5 = Second field of further definiens (five decimal digits). Two cases must be distinguished:
x1 … x5 = 00000 to 99998 identifies catalog(s) of the supplier(s) by referring to the supplier's list
x1 … x5 = 99999; no specific information is given by x1
x6x7 = Identifies an envelope of basic code ("type" part), completing the classification subsystem corresponding to the <bc> in a one-to-one correspondence
y0y1 = These digits provide cost and efficiency information associated with supplier source for this part. Such values do not influence the <basic code> but are important for selection reasons.
z1 … z5 = Provide supplier information including original supplier and multi-sourcing.
Also supplier's subsidiary and plant in the global supply chain.
Because this particular implementation of DCS had as a special characteristic the exchange of parts among different factories and warehouses, the study that preceded the application of the described method concluded that <o> should be polyvalent, going beyond the level of vendor information to reach the specific origin of each part at plant and country level. In other cases, a more limited perspective of origin identification is followed, where <o> only identifies the company owning the manufacturing plant.